/*  mbed Microcontroller Library
    Copyright (c) 2006-2015 ARM Limited

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
#include "I2C.h"

#if DEVICE_I2C

namespace mbed {

    I2C* I2C::_owner = NULL;

    I2C::I2C(PinName sda, PinName scl) :
        #if DEVICE_I2C_ASYNCH
        _irq(this), _usage(DMA_USAGE_NEVER),
        #endif
        _i2c(), _hz(100000) {
        // The init function also set the frequency to 100000
        i2c_init(&_i2c, sda, scl);

        // Used to avoid unnecessary frequency updates
        _owner = this;
    }

    void I2C::frequency(int hz) {
        _hz = hz;

        // We want to update the frequency even if we are already the bus owners
        i2c_frequency(&_i2c, _hz);

        // Updating the frequency of the bus we become the owners of it
        _owner = this;
    }

    void I2C::aquire() {
        if (_owner != this) {
            i2c_frequency(&_i2c, _hz);
            _owner = this;
        }
    }

    // write - Master Transmitter Mode
    int I2C::write(int address, const char* data, int length, bool repeated) {
        aquire();

        int stop = (repeated) ? 0 : 1;
        int written = i2c_write(&_i2c, address, data, length, stop);

        return length != written;
    }

    int I2C::write(int data) {
        return i2c_byte_write(&_i2c, data);
    }

    // read - Master Reciever Mode
    int I2C::read(int address, char* data, int length, bool repeated) {
        aquire();

        int stop = (repeated) ? 0 : 1;
        int read = i2c_read(&_i2c, address, data, length, stop);

        return length != read;
    }

    int I2C::read(int ack) {
        if (ack) {
            return i2c_byte_read(&_i2c, 0);
        } else {
            return i2c_byte_read(&_i2c, 1);
        }
    }

    void I2C::start(void) {
        i2c_start(&_i2c);
    }

    void I2C::stop(void) {
        i2c_stop(&_i2c);
    }

    #if DEVICE_I2C_ASYNCH

    int I2C::transfer(int address, const char* tx_buffer, int tx_length, char* rx_buffer, int rx_length,
                      const event_callback_t& callback, int event, bool repeated) {
        if (i2c_active(&_i2c)) {
            return -1; // transaction ongoing
        }
        aquire();

        _callback = callback;
        int stop = (repeated) ? 0 : 1;
        _irq.callback(&I2C::irq_handler_asynch);
        i2c_transfer_asynch(&_i2c, (void*)tx_buffer, tx_length, (void*)rx_buffer, rx_length, address, stop, _irq.entry(), event,
                            _usage);
        return 0;
    }

    void I2C::abort_transfer(void) {
        i2c_abort_asynch(&_i2c);
    }

    void I2C::irq_handler_asynch(void) {
        int event = i2c_irq_handler_asynch(&_i2c);
        if (_callback && event) {
            _callback.call(event);
        }

    }


    #endif

} // namespace mbed

#endif
